A Comprehensive Survey on Internet of Things (IoT), Architecture, Protocols, and Applications

Abstract

Internet of Things (IoT) is the phenomenon of digital environment that allows to transfer usual physical devices into computerized ones collecting, processing and sharing information via internet in small amount of human interaction. IoT, running on the next generation of embedded systems, wireless communications, and cloud computing, makes innovation possible in many fields, including healthcare, smart cities, agriculture, industrial automation, environmental surveillance. IoT systems, in which sensors, actuators, and data processing units are installed in real things, enable intelligent ecosystems to make the border between the real and the virtual worlds permeable. Generally designed in multi-lateral systems, with IoT being categorized in to perception, network and application layers, it guarantees the scalability and security of deploying systems. A multiplicity of protocols to support the varying degrees of interoperability and communication issues between heterogeneous devices have been invented to suit the various constraints on the power base, latency, bandwidth and mobility requirements. But with the evolvement of IoT, it has various challenges to contend with concerning standardization, security, data privacy, energy consumption and management of the devices. The paper gives an in-depth summary of the IoT ecosystem referring to its architecture, communication standards, and key areas of application, and is of great interest to the research, development, and practice researchers and developers who want to establish and develop efficient and productive IoT systems.

Introduction

The Internet of Things (IoT) refers to a network of interconnected physical devices embedded with sensors, software, and connectivity to collect, process, and exchange data with minimal human intervention. It bridges the physical and digital worlds, enabling smart environments across diverse sectors such as healthcare, agriculture, smart cities, and industrial automation.

2. IoT Fundamentals

• Definition & Evolution: Coined in the late 1990s, IoT has grown rapidly due to advances in wireless communication, cloud computing, and embedded systems.

• Key Characteristics:

  • Interconnectivity

  • Autonomous operation

  • Scalability

  • Context-awareness

  • Intelligence (via AI/ML)

  • Heterogeneity

  • Low power consumption

• Core Components:

  1. Sensors/Actuators (data collection/action)

  2. Connectivity Modules (Wi-Fi, ZigBee, 5G)

  3. Data Processing Units (edge/cloud)

3. Challenges in IoT Development

• Security & Privacy risks due to distributed architecture

• Interoperability issues across diverse platforms

• Scalability of large networks

• Energy constraints in battery-powered devices

• Big Data management

• High deployment cost and complexity

4. IoT Architecture

IoT systems follow a layered architecture:

1. Perception Layer – Sensors/actuators interact with physical environment.

2. Network Layer – Transfers data securely to cloud or middleware.

3. Middleware Layer – Manages devices, data filtering, and analytics.

4. Application Layer – Delivers user-facing services (e.g., smart homes, health apps).

Complementary Architectures:

• Edge Computing – Processes data at or near the device level for low-latency needs.

• Fog Computing – Distributed computing close to data source, enhancing speed and privacy.

• Cloud Computing – Centralized, scalable storage and analysis using platforms like AWS IoT, Azure IoT, etc.

Interoperability Challenges:

• Multiple communication protocols

• Heterogeneous devices

• Lack of standardization

• Data silos

• Integration complexity

5. IoT Communication Protocols

Communication protocols ensure reliable, scalable, and efficient data exchange across IoT devices. These are implemented across the OSI layers:

• Perception Layer:

  • RFID, NFC, ZigBee, Bluetooth/BLE: Short-range, low-power communication.

• Network Layer:

  • IPv6, 6LoWPAN, RPL: For addressing and routing data in constrained networks.

• Transport Layer:

  • TCP/UDP: Reliable or real-time data transfer.

• Application Layer:

  • MQTT (lightweight publish-subscribe)

  • CoAP (web-like protocol for constrained devices)

  • AMQP (secure message routing)

Protocol selection depends on:

• Power efficiency

• Latency requirements

• Bandwidth capacity

• Interoperability

• Application-specific needs

Conclusion

The Internet of Things is changing the way devices are connected, processed and acted upon based on real-life scenarios. This survey has given a broad picture of the architecture of IoT, important communication protocols, applications and security models. We studied gradation of IoT systems, described the meaning of edge/fog/cloud computing, and named the examples of implementation in particular domains starting with smart homes and going to industrial automation. Such current issues as interoperability, energy efficiency, data management, and security concerns were discussed as well. To the academic community, this survey will give lessons about center concepts, future lines of research. It presents opportunities of innovation and optimization of industries. In the future in which IoT is progressing, interdisciplinary collaboration, the ethics of technological development, and self-sustaining technological progress will be prerequisites in achieving what it is capable of transforming completely.

References

[1] Kailas, V., Nivrutti, S., & Atul, S. (2024). A Detailed Study of An Internet of Things (IoT): Review, Recent Research Directions and Complete Journey Towards Sustainable and Smart Future. International Journal of Advanced Research in Science, Communication and Technology. https://doi.org/10.48175/ijarsct-19373. [2] Maheshwary, P. (2024). Review of: “Internet of Things in Smart Grid: A Comprehensive Review of Opportunities, Trends, and Challenges.” https://doi.org/10.32388/puzzjl [3] Bhattacharya, S., Kumar, R., & Singh, S. (2020). Capturing the salient aspects of IoT research: A Social Network Analysis. Scientometrics, 125(1), 361–384. https://doi.org/10.1007/S11192-020-03620-4 [4] Arshi, O., & Chaudhary, A. (2024). Fundamental Concepts of IoT. 42–69. https://doi.org/10.1201/9781032656694-2 [5] Jha, M. K., Singh, M., & Sahoo, A. (2021). Fundamental Principles of IoT (pp. 1–25). IGI Global. https://doi.org/10.4018/978-1-7998-4775-5.CH001 [6] Tamrakar, A. K., Shukla, A., Kalifullah, A. H., Reegu, F., & Shukla, K. (2022). extended review on internet of things (IoT) and its characterisation. International Journal of Health Sciences (IJHS), 8490–8500. https://doi.org/10.53730/ijhs.v6ns2.717 [7] Gubbi, J., Buyya, R., Marusic, S., & Palaniswami, M. (2013). Internet of Things (IoT): A vision, architectural elements, and future directions. Future Generation Computer Systems, 29(7), 1645–1660. https://doi.org/10.1016/j.future.2013.01.010 [8] Al-Fuqaha, A., Guizani, M., Mohammadi, M., Aledhari, M., & Ayyash, M. (2015). Internet of Things: A survey on enabling technologies, protocols, and applications. IEEE Communications Surveys & Tutorials, 17(4), 2347–2376. https://doi.org/10.1109/COMST.2015.2444095 [9] A. A. Mohammed, M. S. Hossain, M. A. Rahman, M. A. Alzain, and M. A. Alshamrani, \"Internet of Things: A comprehensive overview, architectures, applications, simulation tools, challenges and future directions,\" Discover Internet of Things, vol. 4, no. 1, pp. 1–33, 2024. [Online]. Available: https://doi.org/10.1007/s43926-024-00084-3 [10] J. Dizdarevi?, F. Carpio, A. Jukan, and X. Masip-Bruin, \"A Survey of Communication Protocols for Internet-of-Things and Related Challenges of Fog and Cloud Computing Integration,\" Int. J. Distrib. Sens. Netw., vol. 14, no. 7, pp. 1–26, Jul. 2018, [11] P. Shao et al., “A review of IoT applications in healthcare,” Neurocomputing, vol. 565, Jan. 2024, Art. no. 127017. [12] M. R. Karim, A. Al-Ameen, K. Sultana, M. K. D. Hossain, and M. R. Hasan, “A comprehensive survey on IoT and AI based applications in different pre harvest, during harvest and post harvest activities of smart agriculture,” Comput. Electron. Agric., vol. 216, Jan. 2024, [13] H.?Mrabet, S.?Belguith, A.?Alhomoud, and A.?Jemai, “A survey of IoT security based on a layered architecture of sensing and data analysis,” Sensors, vol. 20, no. 13, Art. no.?3625, Jul. 2020. [14] U.?Tariq, I.?Ahmed, A.?K.?Bashir, and K.?Shaukat, “A Critical Cybersecurity Analysis and Future Research Directions for the Internet of Things: A Comprehensive Review,” Sensors, vol.?23, no.?8, Art. no.?4117, 2023. [15] M. Z. Khan, O. H. Alhazmi, M. A. Javed, H. Ghandorh, and K. S. Aloufi, “Reliable Internet of Things: Challenges and Future Trends,” Electronics, vol. 10, no. 19, art. 2377, Sep. 2021.

Copyright

Copyright © 2025 Deepali Kawthekar, Pallavi Dakhore, Kalyani Shevatekar , Bharat Shelke, Prajkta More. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.